Wayrilz (Rezabrutinib) is an oral Bruton's Tyrosine Kinase inhibitor. Approved by the U.S. FDA in 2025, it is indicated for the treatment of persistent or chronic immune thrombocytopenia in adults who have had an inadequate response to previous treatments.

What Are the Side Effects of Wayrilz (Rezabrutinib)?

Gastrointestinal Reactions

Diarrhea (32%, all Grade 1–2).

Nausea (20%, all Grade 1–2).

Abdominal pain (14%, all Grade 1–2).

Vomiting (7%).

Dyspepsia (5%).

Systemic Reactions

Headache (18%).

COVID-19 infection (14%).

Arthralgia (9%).

Dizziness (8%).

Nasopharyngitis (7%).

Severe Side Effects of Wayrilz (Rezabrutinib) Requiring High Alert

Risk of Severe Infections

The incidence of severe infections is increased in patients receiving BTK inhibitor treatment.

These infections include bacterial, viral, and fungal infections.

Hepatotoxicity and Drug-Induced Liver Injury (DILI)

Severe, life-threatening, or even fatal drug-induced liver injury may occur.

Elevated liver transaminases were observed in clinical trials, most of which were mild to moderate.

Precautions for Using Wayrilz (Rezabrutinib)

Contraindications and Dosage

No absolute contraindications.

Recommended dosage: 400 mg orally, twice daily.

Swallow the tablet whole; do not cut, crush, or chew it.

Drugs Prohibited for Concomitant Use

Strong or moderate CYP3A inhibitors.

Strong or moderate CYP3A inducers.

Proton pump inhibitors.

Medication Guidelines for Special Populations

Patients with hepatic impairment: Avoid use in patients with moderate or severe hepatic impairment.

Patients with renal impairment: Avoid use in patients with severe renal impairment.

Pregnancy and lactation:

Women of childbearing age should undergo pregnancy testing before initiating medication.

Effective contraceptive measures must be used during treatment and for 1 week after the last dose.

Lactating women should avoid breastfeeding during treatment and for at least 1 week after the last dose.

Baseline Assessments

Testing of bilirubin and transaminase levels.

Confirmation of pregnancy status in women of childbearing age.

Monitoring During Treatment

Signs and symptoms of infection.

Clinical manifestations of abnormal liver function.

If drug-induced liver injury is suspected, discontinue the medication immediately.